1. Field of the Invention
The present invention relates to an X-ray radiographic apparatus and an X-ray radiographic method for radiographing a subject by detecting an X-ray applied from an X-ray tube to the subject, and more particularly to a technique for performing an X-ray radiography of the subject, employing a filter for extracting the X-ray components, and also relates to an X-ray restrictor used in the X-ray radiographic apparatus.
2. Description of the Related Art
In related art, when the X-ray radiographic apparatus is employed to make the angiography for the lower limb, simultaneously for both legs, a contrast medium is injected into the blood vessel of the subject, and the contrast medium flowing within the blood vessel from the lumber region to the toe is radiographed with the X-ray radiographic apparatus. During this radiography, a holding member (e.g., C-type arm) for holding an X-ray tube and an X-ray detector (image intensifier) for the X-ray radiographic apparatus, or a table top board for laying the subject thereon is being moved continuously or stepwise from the lumber region to the toe.
However, the related-art X-ray radiographic apparatus had a problem that when the radiography is performed using a filter for extracting the X-ray components, the operator had a burden with the operation of the filter and the radiography becomes difficult. For example, when the angiography for the lower limb is made simultaneously for both legs, some halation occurs in the radiographed image because the transmission factor of X-rays is different between a leg portion and a portion between both legs. To prevent the halation, if a specific mat is placed between both legs of the subject, the operator has more burden with the mat. Also, the halation may be prevented by placing the filter near a bulb of the X-ray tube, in which the center of the radiographed image of the lumber region is hidden by the filter, making the radiography difficult.